Witness testimony at the trial, which began April 7, has been temporarily put on hold as the Crown and the defence argue about the annual report on internal audits 2009-10, issued by the Senate internal economy committee.
Duffy has pleaded not guilty to 31 charges of fraud, breach of trust and bribery related to expenses he claimed as a senator and later repaid with money provided by the prime minister's former chief of staff, Nigel Wright.
Duffy's lawyer, Donald Bayne, is expected to finish his arguments this morning, giving the Crown its chance to make the case against admissibility of the report.
The Crown believes the report shouldn't be considered as evidence, claiming its conclusions are hearsay.
While Bayne has agreed that the report is hearsay, he argued in court on Monday that the report is an exception to the hearsay rule.
Bayne said the report should be admissible because it's a public document — it was made by public officials, intended to be a permanent record and accessible to the public — meaning it is has "inherent reliability."
The report included the findings of three audits carried out over the previous year by independent auditing firm Ernst and Young — including one that dealt specifically with senators' office expenditures.
In its report to the committee, the auditors noted the Senate "should provide clearer guidance and criteria on which activities constitute a parliamentary function." During the trial, Bayne has argued that the rules guiding senators were ambiguous and unclear.
Bayne argued that the report didn't merely repeat or rubber stamp the findings of Ernst and Young, but was reviewed and validated by the Senate audit subcommittee — which includes the clerk of the Senate and senior Senate administrative management — as well as the internal economy committee.
Ontario Court of Justice Judge Charles Vaillancourt said it could take him until sometime in June to reach a decision on the issue. But the court will continue to hear from other witnesses after the Crown and defence have completed their legal arguments.